Liquefied gas dispensing system



Aug. 14, 1951 .1. c. FLEMING LIQUEFIEDAGAS DISPENSING SYSTEM Filed May 22, 1944 Patented Aug. 14, 1951 LIQUEFIED GAS DISPENSING SYS-TEM James C. Fleming, Lubbock, Tex., assigner of onehalf to Riobin Baker, Plainview, Tex.

Application May 22, 1944', Serial No. 536,760

7 Claims.

This invention relates to an improvement in liquefied gas dispensing systems, such as may be used for vaporizing and dispensing lqueed gases of the type of butane or-butane mixtures.

Such liquefied. gases. are ordinarily held in liquid. form within a tank, frequently buried underground, under'suicient pressure to maintain the gas in liquid phase. Then when the gas is withdrawn from the tank and its pressure reduced, it flashes into. vaporA which may be conveyed to the burner or point. of use. These systems have usually required some form of vaporizer to aid in vaporizing the liquid withdrawn from the tank, and/or after its: pressure is reduced. Where this vaporizer is mounted in the tankv or attached thereto, the construction is expensive and has other objectionable characteristics.

An object, of this invention is to simplify and improve the construction of the liquefied gas system to: enable the equipment to be manufactured inexpensively, to be assembledv without difliculty and be repaired whenv desired Without disturbing the installation of the storage container.

A further object of the invention is to provide a thermo-syphonic circulating system for utilizing the liquid in the tank in aiding the vaporization of the withdrawn liquefied gas, but in a manner which will nevertheless maintain a circulation of Warm liquid from within the tank in heat exchange relation with the vaporized gas. This is accomplished by positioning the vaporizer in an upright position over the tank and circulating the vaporized fuel downwardly therethrough in heat exchange relation with the liquid in the vaporizer sov as to facilitate the thermo-syphonic circulation therethrough of the liquid in the tank.

The vaporizer is also mounted detachably relative to the tank so that it may be disconnected therefrom for repair, and the first-stage pressure reducing regulator is so arranged Iwith respect to` the vaporizer that it will facilitate the thermosyphonic circulation, but it will also utilize. the warming effect of the liqueiied gas withdrawn from the tank in thermo-syphonic circulation to Warm the port of the first-stage regulator and tend to prevent freezing thereof.

An embodiment of the invention is illustrated in the accompanying drawing Whichrepresents a. partial vertical section through a liquefied gas tank showing the invention applied thereto, with parts in elevation.

The pressure storage tank is designated generally by the numeral I and. is of the character ordinarly used for storing highly Volatile liquefied petroleum gas, such as butane; or a mixture cntaining butane. The tank I may be buried underground as usual, if desired, which is often required to maintain practical' operation conti-nuously, particularly in cold climates. The tankl I is adapted to be lled and gauged in the usual way, as by the stand-pipe 2, having a head 3 thereon provided with the usual ttings for filling, gauging the pressure, etc. Where the tank is buried underground, these parts are usually enclosed within a surrounding casing provided with a removable cover for access thereto.

In the example show-n, the tank I is provided with a heat exchanger, designated generally at 4, which is constructed as an enclosed casing or container surmounted on the tank, detachable therefrom, by means of a coupling or union 5. The heat exchanger 4 is elongated' vertically in upstanding relation from the top of the tank. The lower end of the heat exchanger 4 is detachably connected byy the union 5 with the upper end of a return pipe 6 extending upwardly through the topy of the tankv and preferably welded thereto. The return pipe 6 has a cut-ofivalve l' therein. The return pipe G extendsdownwardly in the tank I to a point near the bottom thereof.

Mounted upon the upper end of the heat exchanger 4 is a chamber 8, detachably connected with the heat exchanger 4, as by a union 9. These parts 4, 6 and 8 are thus detachable from each other, capable of being separated for detachment of the chamber 8, as Iwell as the heat exchanger, from the other parts of the system, particularly when repair may be necessary or desirable, without disturbing the storage tank I. The separate construction and detachable connection of thev top chamber 8 and heat exchanger 4 facilitates the construction of the system in an economical manner, as Well as repair of any of these parts readily.

The chamber 8 has a withdrawal |pipe I0 connected with a side thereof and extending downwardly therefrom beside the heat exchanger 4v through the top of the tank I. to which. it may Abe welded` if desired, and to a point adjacent the bottom of. the tank, as indicated in the drawing., This pipe Ill will supply liquefied gas from within the tank to the chamber 8, as hereinafter described.

The withdrawal pipe, I- has a cut-off valveV Il therein preferably located adjacent the top of. the tank to provide a detachable connection of the super-structure therewith, as well as to; control or discontinue the flow. The pipe Ill is. de.- tachably connected with the chamber 8 by means 3 of a union I2 to permit the chamber to be disconnected therefrom.

The pipe I9 also is provided with a T I3 therei in connected by a return tube I4 extending therefrom to the head 3 for communication to the stand-pipe 2, with the connection from said return tube I4 to the stand-pipe 2 controlled by a valve I5 in the head.

Also mounted within or at one side of the chamber 8 is a pressure reducing regulator, designated generally at I6, which is shown as of the usual form of diaphragm-operated valve having adjusting springs acting thereon, so as to control the passage of fuel therethrough. The regulator I6 has an inlet at Il to one side of the valve thereof, and an outlet at I8 from the opposite side of the valve thereof. The inlet I'I is located at or substantially above the highest point of the withdrawal pipe lil and the point of connection thereof with the chamber 8. Extending from the outlet I8 and connected therewith, is a tube I9 that extends downwardly through the vaporizer 4 substantially throughout the length thereof and is turned back and outwardly therefrom at the top thereof. The tube I9 preferably has an extended length within the vaporizercontainer 4, such as will be provided by a coil 20, to aid in the transfer of heat from the liquid within the vaporizer container 'to the gas or liquid within the coil. The tube I9 extends from the vaporizer 4 to a second-stage pressure regulator 2i, which may be of the usual character employed in liquefied gas dispensing systems, shown as mounted on the stand-pipe 2. From said regulator ZI a service pipe 22 extends to the gas burner or other point of use.

The chamber 8 is in open communication with the chamber in the vaporizer 4, through nipples connected together by the union 9.

The liquefied gas is conned in the tank I under a pressure of approximately forty pounds per square inch. The first-stage pressure reducing regulator I6 is set ordinarily to operate at approximately five pounds per square inch. The second-stage pressure reducing regulator 2| is set to operate ordinarily at approximately six ounces.

When no gas is being consumed at the burner or drawn oii from the service pipe 22 and the system is dormant, the liquid will stand at approximately the same height in the pipes and I0.. However, when gas is being consumed, this will reduce the pressure in the pipe lli-22 which will then operate to open the valve in the regulator I6, and this in turn will decrease the pressure in the chamber 3 and Vaporizer 4, as well as in the pipes 6 and I0. This reduction in'pressure will cause the liquid to rise in the pipes 5 and Il) due to the suction thus caused therein until the liquid from the tank I fills these pipes and also the vaporizer 4 and chamber 8, passing into the inlet I`I of the regulator I6.

As the liquefied gas passes through the regulator I6, the reduction in pressure on the outlet side thereof is sufficient to cause an expansion of the gases tovaporization thereof, and the vaporized gases, then pass off through the tube I9 to the point of use. Refrigeration takes place in the chamber 8, because of the expansion of the gases at the regulator, and the expanded gases passing through the coil Z often have a temperature below freezing, and sometimes are accompanied by some liquid which fails-to vaporize or which may become liquid again after leaving the regulator. 'Ihe lower temperature thus present in the coil 20 than is present in the liquid in the vaporizer 4, causes some of the heat from the liquid in the vaporizer to be given up to the gas in the coil, thus aiding in Vaporizing or maintaining the vaporizing of the gas therein.

As the heat from the liquid in the vaporizer 4 is thus given up to the coil 20, the liquid in the vaporizer will be cooled at its lower portion with respect to the liquid that enters the upper part of the structure 4, 8, so that the cooler liquid will have a tendency to move downward through the pipe 6 into the tank. This in turn will allow a circulation of warm liquid from within the tank upward through the withdrawal pipe IIl into the chamber B.

After the system is in operation, this thermosyphonic circulation will continue to be maintained, thereby circulating warmed liquid from within the tank into the vaporizer 4 in heat exchange relation with the tube I9 and coil 2B, to vaporize the gas passing therethrough or any part of said gas that may require vaporization.

This system will also cause .circulation of warmed liquefied gas around the outside of the regulator I6, the portion thereof contained within the chamber 8. This circulation will be sufficient to warm the regulator at the point where refrigeration normally takes place, and thus tends to prevent the freezing of the valve of the regulator, which would otherwise impair the efliciency of the system. Moreover, it will be noted that the inlet I1 of the regulator I6 is located directly at the top of the chamber 8, so that it receives therein the warmed liquid directly from the withdrawal pipe I0. This facilitates vaporization because the warm liquefied gas vaporizes much more readily than after' it has been cooled appreciably.

During the normal operation of the system on liquid withdrawal, the valve I5 will remain closed However, the valve I5 may be opened to allow the tank pressure of vaporized gas above the liquid in the tank I to be turned into the thermo-circulating system, thereby forcing all liquid from within the pipes 6 and I0, the Vaporizer 4 and the chamber 8, back into the tank I. Then upon closing of the valves 'I and II, there will be only vaporized gas in the superstructure. This will prevent the loss of any liquid when the parts are disassembled. It is also possible with this structure to disconnect the tube I4 from the T I3 and extend it from the head 3 directly to the regulatorv 2|, when the system may be operated on batch Vaporization. The vaporized fuel in the top of the tank I will then pass olf through the stand-pipe 2 and out of the head 3, through the tube I4 directly to the regulator 2|, thence to the service pipe 22. Such direct operation or batch vaporization may be desirable, for instance, when the vaporizer 4 or the chamber 8 may require disconnection for repair.

The system thus provides for more efficient vaporization of the liquefied gas, with improved operation, and yet is simple and inexpensive to Iconstruct. Moreover, the parts are detachably connected together so that they may be separated for repair without disturbing the installation of the storage tank in the' ground.

I claim: Y

l. In a liquefied gas dispensing system, a vaporiZ-eicomprising an upright chamber adapted to contain a heat exchange medium therein, a tube extending through said chamber for circulating vaporized fuel therethrough without mixture with the liquid in the vaporizer, a pressure reducing regulator mounted at the upper end of said vaporizer and having a discharge side connected with said tube and an inlet adapted to receive liquefied fuel therein, and a chamber mounted on the vaporizer and at least partially enclosing the regulator in open communication with the inlet thereof.

2. In a liquefied gas dispensing system, a vaporizer comprising an upright chamber adapted to contain a heat exchange medium therein, a tube extending through said chamber for circulating vaporized fuel therethrough without mixture with the liquid in the vapcrizer, a pressure reducing regulator mounted at the upper end of said vaporizer and having a discharge side connected with said tube and an inlet adapted to receive liquefied fuel therein, a chamber mounted on the vaporizer and at least partially enclosing the regulator in open communication with the inlet thereof, said last-mentioned chamber being in open communication with the vaporizer chamber, and means for circulating liquid into the second-mentioned chamber in heat exchange relation with the regulator and downwardly through the vaporizer in heat exchange relation with the tube therein.

3. In a liquefied gas dispensing system, the combination of a tank adapted to contain liquefled gas under pressure, a substantially inverted U-shaped conduit structure having the side arms thereof extending downwardly into the tank through the top thereof to a point adjacent the bottom of the tank and open therein for thermosyphonic circulation of liqueed gas from within the tank through said conduit structure, means connected with said conduit structure for reducing the pressure of a portion of the liqueed gas circulating therethrough and vaporizing said gas for directing said vaporized gas to a `point of consumption, valve means connected in the opposite sides of the inverted U-shaped conduit structure adjacent the top of the tank for closing said conduit structure against upward flow of gas therethrough from the tank, and means for detachably mounting the pressure reducing and vaporizng means and the upper portion of the conduit structure on the tank for detachment thereof from the tank upon closing of said valve means.

4. In a liquefied gas dispensing system, the combination of a tank adapted to contain liqueed gas under pressure, a substantially inverted U-shaned conduit structure having the side arms thereof extending downwardly into the tank through the top thereof to a point adjacent the bottom of the tank and open therein for thermosvphonic circulation of lioueed gas from within the tank through said conduit structure, means connected within said conduit structure for reducing the pressure of a portion of the liqueiied gas circulating therethrough and vaporizing said gas and for directing said vaporized gas to a point of consumption, valves connected in the side arms of the conduit structure for closing the conduit structure against the upward ilow of gas therethrough from within the tank, and means detachably mounting the pressure reducing and vaporizing means and the upper portion of the conduit structure on the tank in the conduit structure for detachment thereof from the tank.

5. In a liquefied gas dispensing system, the combination of a tank adapted to contain liqueed gas under pressure, a substantially inverted U-shaped conduit structure having the side arms thereof extending downwardly into the tank through the top thereof to a point adjacent the bottom of the tank and open therein for thermosyphonic circulation of liquefied gas from within the tank through said conduit structure, means connected with said conduit structure for reducing the pressure of a portion of the liquefied gas circulating therethrough and vaporizing said gas for directing said vaporized gas to a point oi. consumption, valve means connected in the opposite sides of the inverted U-shaped conduit structure adjacent the top of the tank for closing said conduit structure against upward flow of gas therethrough from the tank, means for detachably mounting the pressure reducing and vaporizing means and the upper portion of the conduit structure on the tank for detachment thereof .from the tank upon closing of said valve means, and means for directing gas pressure from the top of the tank to the top portion of the conduit structure for forcing the liqueed gas therefrom back into the tank.

6. In a liqueiied gas dispensing system, the combination of a tank adapted to contain liqueed gas under pressure, a substantially inverted U-shaped conduit structure having the side arms thereof extending downwardly into the tank through the top thereof to a point adjacent the bottom of the tank and open therein for thermosyphonic circulation of liquefied gas from within the tank through said conduit structure, means connected with said conduit structure for reducing the pressure of a portion of the liquefied gas circulating therethrough and vaporizing said gas and for directing said vaporized gas to a point of consumption, pressure reducing means connected with the conduit structure for reducing the pressure of the gas and vaporizing said gas for supply to a point of consumption, a stand-pipe connected with the top of the tank and extending upwardly therefrom, a head mounted on the stand-pipe and having a control valve therein, and a tube connected with said valve and with the upper portion of the conduit structure for communication through said head from the stand-pipe to the top portion of the conduit structure.

'7. In a liqueed gas dispensing system, a vaporizer comprising an elongated chamber adapted to contain a heat exchange medium therein, a tube extending through said chamber for circulating vaporized fuel therethrough without mixture with the liquid in the vaporizer, a pressure reducing regulator mounted at one end of said vaporizer and having a discharge side connected with said tube and an inlet adapted to receive liqueed fuel therein, and a chamber mounted on the vaporizer and at least partially enclosing the regulator in open communication with the inlet thereof.

JAMES C. FLEMING.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 2,050,750 Drummond Aug. 1l, 1936 2,285,050 Baker et al. June 9, 1942 2,335,837 Abramson Nov. 30, 1943 2,378,077 Garretson June 12, 1945 

